| Index: src/third_party/computer_language_benchmarks_game/nbody.c
|
| diff --git a/src/third_party/computer_language_benchmarks_game/nbody.c b/src/third_party/computer_language_benchmarks_game/nbody.c
|
| deleted file mode 100644
|
| index d68e8f01f21d1b43737a3a6d9fe2cc265d146d3f..0000000000000000000000000000000000000000
|
| --- a/src/third_party/computer_language_benchmarks_game/nbody.c
|
| +++ /dev/null
|
| @@ -1,169 +0,0 @@
|
| -/* The Computer Language Benchmarks Game
|
| - * http://benchmarksgame.alioth.debian.org/
|
| - *
|
| - * contributed by Christoph Bauer
|
| - * slightly sped up by Petr Prokhorenkov
|
| - */
|
| -
|
| -#include <math.h>
|
| -#include <stdio.h>
|
| -#include <stdlib.h>
|
| -
|
| -#define pi 3.141592653589793
|
| -#define solar_mass (4 * pi * pi)
|
| -#define days_per_year 365.24
|
| -
|
| -struct planet {
|
| - double x, y, z;
|
| - double vx, vy, vz;
|
| - double mass;
|
| -};
|
| -
|
| -/*
|
| - * Here's one weird thing: inlining of this function
|
| - * decreases performance by 25%. (I.e. do not compile this with -O3)
|
| - * Advances with dt == 1.0
|
| - */
|
| -void advance(int nbodies, struct planet * bodies)
|
| -{
|
| - int i, j;
|
| -
|
| - for (i = 0; i < nbodies; i++) {
|
| - struct planet * b = &(bodies[i]);
|
| - for (j = i + 1; j < nbodies; j++) {
|
| - struct planet * b2 = &(bodies[j]);
|
| - double dx = b->x - b2->x;
|
| - double dy = b->y - b2->y;
|
| - double dz = b->z - b2->z;
|
| - double inv_distance = 1.0/sqrt(dx * dx + dy * dy + dz * dz);
|
| - double mag = inv_distance * inv_distance * inv_distance;
|
| - b->vx -= dx * b2->mass * mag;
|
| - b->vy -= dy * b2->mass * mag;
|
| - b->vz -= dz * b2->mass * mag;
|
| - b2->vx += dx * b->mass * mag;
|
| - b2->vy += dy * b->mass * mag;
|
| - b2->vz += dz * b->mass * mag;
|
| - }
|
| - }
|
| - for (i = 0; i < nbodies; i++) {
|
| - struct planet * b = &(bodies[i]);
|
| - b->x += b->vx;
|
| - b->y += b->vy;
|
| - b->z += b->vz;
|
| - }
|
| -}
|
| -
|
| -double energy(int nbodies, struct planet * bodies)
|
| -{
|
| - double e;
|
| - int i, j;
|
| -
|
| - e = 0.0;
|
| - for (i = 0; i < nbodies; i++) {
|
| - struct planet * b = &(bodies[i]);
|
| - e += 0.5 * b->mass * (b->vx * b->vx + b->vy * b->vy + b->vz * b->vz);
|
| - for (j = i + 1; j < nbodies; j++) {
|
| - struct planet * b2 = &(bodies[j]);
|
| - double dx = b->x - b2->x;
|
| - double dy = b->y - b2->y;
|
| - double dz = b->z - b2->z;
|
| - double distance = sqrt(dx * dx + dy * dy + dz * dz);
|
| - e -= (b->mass * b2->mass) / distance;
|
| - }
|
| - }
|
| - return e;
|
| -}
|
| -
|
| -void offset_momentum(int nbodies, struct planet * bodies)
|
| -{
|
| - double px = 0.0, py = 0.0, pz = 0.0;
|
| - int i;
|
| - for (i = 0; i < nbodies; i++) {
|
| - px += bodies[i].vx * bodies[i].mass;
|
| - py += bodies[i].vy * bodies[i].mass;
|
| - pz += bodies[i].vz * bodies[i].mass;
|
| - }
|
| - bodies[0].vx = - px / solar_mass;
|
| - bodies[0].vy = - py / solar_mass;
|
| - bodies[0].vz = - pz / solar_mass;
|
| -}
|
| -
|
| -#define NBODIES 5
|
| -struct planet bodies[NBODIES] = {
|
| - { /* sun */
|
| - 0, 0, 0, 0, 0, 0, solar_mass
|
| - },
|
| - { /* jupiter */
|
| - 4.84143144246472090e+00,
|
| - -1.16032004402742839e+00,
|
| - -1.03622044471123109e-01,
|
| - 1.66007664274403694e-03 * days_per_year,
|
| - 7.69901118419740425e-03 * days_per_year,
|
| - -6.90460016972063023e-05 * days_per_year,
|
| - 9.54791938424326609e-04 * solar_mass
|
| - },
|
| - { /* saturn */
|
| - 8.34336671824457987e+00,
|
| - 4.12479856412430479e+00,
|
| - -4.03523417114321381e-01,
|
| - -2.76742510726862411e-03 * days_per_year,
|
| - 4.99852801234917238e-03 * days_per_year,
|
| - 2.30417297573763929e-05 * days_per_year,
|
| - 2.85885980666130812e-04 * solar_mass
|
| - },
|
| - { /* uranus */
|
| - 1.28943695621391310e+01,
|
| - -1.51111514016986312e+01,
|
| - -2.23307578892655734e-01,
|
| - 2.96460137564761618e-03 * days_per_year,
|
| - 2.37847173959480950e-03 * days_per_year,
|
| - -2.96589568540237556e-05 * days_per_year,
|
| - 4.36624404335156298e-05 * solar_mass
|
| - },
|
| - { /* neptune */
|
| - 1.53796971148509165e+01,
|
| - -2.59193146099879641e+01,
|
| - 1.79258772950371181e-01,
|
| - 2.68067772490389322e-03 * days_per_year,
|
| - 1.62824170038242295e-03 * days_per_year,
|
| - -9.51592254519715870e-05 * days_per_year,
|
| - 5.15138902046611451e-05 * solar_mass
|
| - }
|
| -};
|
| -
|
| -#define DT 1e-2
|
| -#define RECIP_DT (1.0/DT)
|
| -
|
| -/*
|
| - * Rescale certain properties of bodies. That allows doing
|
| - * consequential advance()'s as if dt were equal to 1.0.
|
| - *
|
| - * When all advances done, rescale bodies back to obtain correct energy.
|
| - */
|
| -void scale_bodies(int nbodies, struct planet * bodies, double scale) {
|
| - int i;
|
| -
|
| - for (i = 0; i < nbodies; i++) {
|
| - bodies[i].mass *= scale*scale;
|
| - bodies[i].vx *= scale;
|
| - bodies[i].vy *= scale;
|
| - bodies[i].vz *= scale;
|
| - }
|
| -}
|
| -
|
| -int main(int argc, char ** argv)
|
| -{
|
| - int n = atoi(argv[1]);
|
| - int i;
|
| -
|
| - offset_momentum(NBODIES, bodies);
|
| - printf ("%.9f\n", energy(NBODIES, bodies));
|
| - scale_bodies(NBODIES, bodies, DT);
|
| - for (i = 1; i <= n; i++) {
|
| - advance(NBODIES, bodies);
|
| - }
|
| - scale_bodies(NBODIES, bodies, RECIP_DT);
|
| - printf ("%.9f\n", energy(NBODIES, bodies));
|
| - return 0;
|
| -}
|
| -
|
|
|